From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Laboratory report on the failure analysis of a Wraith No.6 bearing made from A.G.6 alloy.
| Identifier | ExFiles\Box 115\3\ scan0179 | |
| Date | 24th January 1938 | |
| Mthe See me Pm 1080 To - Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} M.1525. Laboratory. H1/4/WJ.24.1.38. WRAITH No.6 BEARING IN A.G.6. ALLOY. (Your Ref. Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell}6/AP.21.1.38). After 2 hours endurance run at 4000 RPM. No.2. unit, the surface of this bearing appeared considerably bruised, but there were very few embedded particles. The magnesium content is on the bottom limit, but we should not attribute the failure to this but to the bearing having been machined from an unsound part of the original casting. The presence of oil filled cracks in the bearing, the variation in hardness - 65 to 75 V.P.N.(10 kg) in parts unaffected by running and the general appearance of the fractures and working surface have led us to this opinion. HR. H1 | ||